Non-crystalline plastics such as polycarbonates, polyphenylene ethers and ABS resins have inadequate heat resistance, chemical resistance and arc resistance. On the other hand, crystalline plastics such as polyesters and polyolefins do by themselves have sufficient arc resistance and tracking resistance, but their flame retardance and heat resistance are inadequate. In polyesters, it is known that sufficient flame retardance and heat resistance can be obtained by the addition of fillers such as halogen-antimony flame retardants and glass fibers. However, a notable decrease in the arc resistance and the tracking resistance can be observed as side effects of these additives.
The object of the present invention is to provide a polyester resin composition having a good arc resistance and tracking resistance, as well as a sufficient heat resistance and flame retardance.